Spot the liar?

Controversially, certain brain scanning techniques such as fMRI and EEG have been used for lie-detection purposes in high-profile court cases in the US and India since 2008. Although fMRI for lie detection is an as-yet unproven technology, scientist Steve Laken says the basic idea behind using fMRI for lie detection is that when you tell the truth, ‘the brain moves relatively fast. You simply don’t have to think about things. To lie, however, you have to first understand the question and then come up with an alternative communication.’ The differences in how the brain behaves when people lie and tell the truth are visible in fMRI scans.